Technology for processing on-screen display is commonly used in most LCD TV and generates controllable information or icon on the screen. Thus, the present status can be displayed when user adjusts the LCD TV. An OSD control chip or a built-in OSD control circuit in the control circuit of LCD TV becomes the key point of the user interface. However, in conventional TV system, the OSD control circuit generates OSD information and blends the OSD information with video signals, and the blended video signal is then de-interlaced. Since the OSD information is a corresponsively still image, the blending of the OSD information and the video signal with motion will cause the difficulty in motion detection of the de-interlace process. The drawback mentioned above would induce indistinct images or color mismatch.